Patents by Inventor Mohammad Saidur Rahaman

Mohammad Saidur Rahaman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11963907
    Abstract: In a laser beam delivery system for an ophthalmic laser system, a single multi-use beam sampler is employed to form three sampled laser beams, including two for redundant laser energy monitoring and one for laser focal point depth measurement. The beam sampler is a transparent plate with preferably parallel front and back surfaces. The front surface reflects a fraction of the incoming beam to form the first sampled beam toward an energy monitoring detector. The back surface reflects another fraction of the beam to form a second sampled beam exiting backwardly from the front surface toward another energy monitoring detector. An objective lens focuses the transmitted beam onto a target, and collects back reflected or scattered light from the target to form a return beam. The back surface of the beam sampler reflects a fraction of the return beam to form the third sampled beam toward a third detector.
    Type: Grant
    Filed: September 20, 2021
    Date of Patent: April 23, 2024
    Assignee: AMO Development, LLC
    Inventors: Mohammad Saidur Rahaman, Hong Fu
  • Patent number: 11957412
    Abstract: An imaging system for an ophthalmic laser system includes a prism cone made of a transparent optical material and disposed downstream of the focusing objective lens of the ophthalmic laser system, the prism cone having an upper surface, a lower surface parallel to the upper surface, a tapered side surface between the upper and lower surfaces, and a beveled surface formed at an upper edge of the prism cone and intersecting the upper surface and the side surface, and a camera disposed adjacent to the prism cone and facing the beveled surface. The camera is disposed to directly receive light that enters the lower surface of the prism cone and exits the beveled surface without having been reflected by any surface.
    Type: Grant
    Filed: November 11, 2019
    Date of Patent: April 16, 2024
    Assignee: AMO Development, LLC
    Inventors: Zenon Witowski, Mohammad Saidur Rahaman, Daryl Wong
  • Publication number: 20240118536
    Abstract: An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.
    Type: Application
    Filed: October 13, 2023
    Publication date: April 11, 2024
    Inventors: Mohammad Saidur Rahaman, Hong Fu, Roger W. Accurso, Zenon Witowski
  • Patent number: 11789256
    Abstract: An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.
    Type: Grant
    Filed: December 9, 2021
    Date of Patent: October 17, 2023
    Assignee: AMO Development, LLC
    Inventors: Mohammad Saidur Rahaman, Hong Fu, Roger W. Accurso, Zenon Witowski
  • Publication number: 20220168144
    Abstract: Embodiments generally relate to ophthalmic laser procedures and, more particularly, to systems and methods for lenticular laser incision. In an embodiment, an ophthalmic surgical laser system comprises a laser delivery system for delivering a pulsed laser beam to a target in a subject's eye, an XY-scan device to deflect the pulsed laser beam, a Z-scan device to modify a depth of a focus of the pulsed laser beam, and a controller configured to form a top lenticular incision and a bottom lenticular incision of a lens in a corneal stroma.
    Type: Application
    Filed: February 15, 2022
    Publication date: June 2, 2022
    Inventors: Alireza Malek Tabrizi, Hong Fu, James E. Hill, Mohammad Saidur Rahaman, Zenon Witowski
  • Publication number: 20220118550
    Abstract: An ophthalmic laser surgical system has a built-in imaging sensor for measuring laser focal spot size. An objective lens focuses the laser beam to a focal spot near a reflective surface, scans the focal spot in the depth direction, and focuses light reflected by the reflective surface to form a back-reflected light. A two-dimensional imaging sensor receives a sample of the back-reflected light to generate images of the back-reflected light. During the depth scan, the image contains a well-focused light spot when the laser focal spot is located at a fixed offset distance before the reflective surface, but the light spot in the images is otherwise defocused. The images generated during the scan are analyzed to find the smallest light spot size among the images. The laser focal spot size is then calculated from the smallest light spot size using a magnification factor which is a system constant.
    Type: Application
    Filed: October 8, 2021
    Publication date: April 21, 2022
    Inventors: Mohammad Saidur Rahaman, Hong Fu
  • Publication number: 20220099961
    Abstract: An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.
    Type: Application
    Filed: December 9, 2021
    Publication date: March 31, 2022
    Inventors: Mohammad Saidur Rahaman, Hong Fu, Roger W. Accurso, Zenon Witowski
  • Publication number: 20220087862
    Abstract: In a laser beam delivery system for an ophthalmic laser system, a single multi-use beam sampler is employed to form three sampled laser beams, including two for redundant laser energy monitoring and one for laser focal point depth measurement. The beam sampler is a transparent plate with preferably parallel front and back surfaces. The front surface reflects a fraction of the incoming beam to form the first sampled beam toward an energy monitoring detector. The back surface reflects another fraction of the beam to form a second sampled beam exiting backwardly from the front surface toward another energy monitoring detector. An objective lens focuses the transmitted beam onto a target, and collects back reflected or scattered light from the target to form a return beam. The back surface of the beam sampler reflects a fraction of the return beam to form the third sampled beam toward a third detector.
    Type: Application
    Filed: September 20, 2021
    Publication date: March 24, 2022
    Inventors: Mohammad Saidur Rahaman, Hong Fu
  • Publication number: 20220062049
    Abstract: A method for forming deep corneal lamellar incision parallel to the posterior corneal surface when the eye is docked to the patient interface. A lower-energy detecting beam generated by the same pulsed laser that generates the higher-energy treatment laser beam is utilized to measure the posterior corneal surface profile. The detecting beam is scanned in the eye according to a first 3-dimensional scan pattern, while intensity of the back-reflected light is measured by a light intensity detector. The first scan pattern may be a spiral pattern in the X-Y plane coupled with a Z direction oscillation function. Peaks of the light intensity signal are detected, and corresponding spatial positions of the focus point are obtained; a known offset distance is added to the depth value to obtain the posterior corneal surface profile. Based thereon, the treatment laser beam is scanned in the eye to form the deep corneal lamellar incision.
    Type: Application
    Filed: August 26, 2021
    Publication date: March 3, 2022
    Inventors: Hong Fu, Mohammad Saidur Rahaman, Alireza Malek Tabrizi, Zenon Witowski, Griffith Altmann
  • Patent number: 11253398
    Abstract: Embodiments generally relate to ophthalmic laser procedures and, more particularly, to systems and methods for lenticular laser incision. In an embodiment, an ophthalmic surgical laser system comprises a laser delivery system for delivering a pulsed laser beam to a target in a subject's eye, an XY-scan device to deflect the pulsed laser beam, a Z-scan device to modify a depth of a focus of the pulsed laser beam, and a controller configured to form a top lenticular incision and a bottom lenticular incision of a lens in a corneal stroma.
    Type: Grant
    Filed: June 22, 2017
    Date of Patent: February 22, 2022
    Assignee: AMO Development, LLC
    Inventors: Alireza Malek Tabrizi, Hong Fu, James E. Hill, Mohammad Saidur Rahaman, Zenon Witowski
  • Patent number: 11215814
    Abstract: An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.
    Type: Grant
    Filed: August 24, 2018
    Date of Patent: January 4, 2022
    Assignee: AMO Development, LLC
    Inventors: Mohammad Saidur Rahaman, Hong Fu, Roger W. Accurso, Zenon Witowski
  • Publication number: 20210275017
    Abstract: An imaging system for an ophthalmic laser system includes a prism cone made of a transparent optical material and disposed downstream of the focusing objective lens of the ophthalmic laser system, the prism cone having an upper surface, a lower surface parallel to the upper surface, a tapered side surface between the upper and lower surfaces, and a beveled surface formed at an upper edge of the prism cone and intersecting the upper surface and the side surface, and a camera disposed adjacent to the prism cone and facing the beveled surface. The camera is disposed to directly receive light that enters the lower surface of the prism cone and exits the beveled surface without having been reflected by any surface.
    Type: Application
    Filed: November 11, 2019
    Publication date: September 9, 2021
    Inventors: Zenon Witowski, Mohammad Saidur Rahaman, Daryl Wong
  • Patent number: 10973688
    Abstract: An ophthalmic laser surgical system uses a confocal detector assembly to continuously detect a confocal signal during laser treatment, and based on the confocal signal, detects in real time a loss of tissue contact with the patient interface (PI) output surface. The detection is partly based on the change of reflectivity at the PI output surface when the optical interface changes from a lens-tissue interface to a lens-air interface. The behavior of the confocal signal upon loss of tissue contact is dependent on the treatment laser scan pattern being performed at the time of tissue contact loss. Thus, different confocal signal analysis algorithms are applied to detect tissue contact loss during different scans, such as the bed cut and side cut for a corneal flap. The real time confocal signal may also be used during eye docking to detect the establishment of tissue contact with the PI output surface.
    Type: Grant
    Filed: March 15, 2019
    Date of Patent: April 13, 2021
    Assignee: AMO Development, LLC
    Inventors: Harvey I. Liu, Mohammad Saidur Rahaman, Hong Fu, Griffith E. Altmann
  • Patent number: 10857031
    Abstract: A femtosecond laser system for ophthalmic applications, which employs a number of chirped mirrors in the laser beam delivery system between the laser head and the objective lens. The chirped mirrors perform the dual function of both turning the laser beam in desired directions and compensating for beam broadening due to group delay dispersion (GDD) of the optical elements of the system. Each chirped mirror reflects the laser beam only once. Four chirped mirrors are used, each providing up to ?5000 fs2 of negative GDD per bounce, to provide a total of ?18,000 fs2 negative GDD to compensate for the positive GDD of +18,000 fs2 introduced by other optical elements in the laser beam delivery system. This eliminates the need for a pulse compressor that would employ a grating pair, prism pair or grism pair, and therefore significantly reduces the size of the system and the alignment requirements.
    Type: Grant
    Filed: February 5, 2018
    Date of Patent: December 8, 2020
    Assignee: AMO Development, LLC
    Inventors: Zenon J. Witowski, Mohammad Saidur Rahaman
  • Publication number: 20200289318
    Abstract: An ophthalmic laser surgical system uses a confocal detector assembly to continuously detect a confocal signal during laser treatment, and based on the confocal signal, detects in real time a loss of tissue contact with the patient interface (PI) output surface. The detection is partly based on the change of reflectivity at the PI output surface when the optical interface changes from a lens-tissue interface to a lens-air interface. The behavior of the confocal signal upon loss of tissue contact is dependent on the treatment laser scan pattern being performed at the time of tissue contact loss. Thus, different confocal signal analysis algorithms are applied to detect tissue contact loss during different scans, such as the bed cut and side cut for a corneal flap. The real time confocal signal may also be used during eye docking to detect the establishment of tissue contact with the PI output surface.
    Type: Application
    Filed: March 15, 2019
    Publication date: September 17, 2020
    Inventors: Harvey I. Liu, Mohammad Saidur Rahaman, Hong Fu, Griffith E. Altmann
  • Publication number: 20200064622
    Abstract: An ophthalmic laser system uses a non-confocal configuration to determine a laser beam focus position relative to the patient interface (PI) surface. The system includes a light intensity detector with no confocal lens or pinhole between the detector and the objective lens. When the objective focuses the light to a target focus point inside the PI lens at a particular offset from its distal surface, the light signal at the detector peaks. The offset value is determined by fixed system parameters, and can also be empirically determined by directly measuring the PI lens surface by observing the effect of plasma formation at the glass surface. During ophthalmic procedures, the laser focus is first scanned insider the PI lens, and the target focus point location is determined from the peak of the detector signal. The known offset value is then added to obtain the location of the PI lens surface.
    Type: Application
    Filed: August 24, 2018
    Publication date: February 27, 2020
    Inventors: Mohammad Saidur Rahaman, Hong Fu, Roger W. Accurso, Zenon Witowski
  • Publication number: 20180221200
    Abstract: A femtosecond laser system for ophthalmic applications, which employs a number of chirped mirrors in the laser beam delivery system between the laser head and the objective lens. The chirped mirrors perform the dual function of both turning the laser beam in desired directions and compensating for beam broadening due to group delay dispersion (GDD) of the optical elements of the system. Each chirped mirror reflects the laser beam only once. Four chirped mirrors are used, each providing up to ?5000 fs2 of negative GDD per bounce, to provide a total of ?18,000 fs2 negative GDD to compensate for the positive GDD of +18,000 fs2 introduced by other optical elements in the laser beam delivery system. This eliminates the need for a pulse compressor that would employ a grating pair, prism pair or grism pair, and therefore significantly reduces the size of the system and the alignment requirements.
    Type: Application
    Filed: February 5, 2018
    Publication date: August 9, 2018
    Inventors: Zenon J. Witowski, Mohammad Saidur Rahaman
  • Publication number: 20170367883
    Abstract: Embodiments generally relate to ophthalmic laser procedures and, more particularly, to systems and methods for lenticular laser incision. In an embodiment, an ophthalmic surgical laser system comprises a laser delivery system for delivering a pulsed laser beam to a target in a subject's eye, an XY-scan device to deflect the pulsed laser beam, a Z-scan device to modify a depth of a focus of the pulsed laser beam, and a controller configured to form a top lenticular incision and a bottom lenticular incision of a lens in a corneal stroma.
    Type: Application
    Filed: June 22, 2017
    Publication date: December 28, 2017
    Inventors: Alireza Malek Tabrizi, Hong Fu, James E. Hill, Mohammad Saidur Rahaman, Zenon Witowski